For $99 MuSA could be a nice hackable platform for all sorts of motion-enabled applications. It has a built-in accelerometer , LCD and a simple casing. Here is the description from ST:
"The platform comes with the LIS331DLH preinstalled on the board, but can support any digitaloutput accelerometer from ST in 3×3 or 3×5 mm packages connected to the microcontroller through an SPI interface, as well as the LIS344ALH analog-output accelerometer.
The MuSA platform features four buttons for navigating the menus. A mini-USB connector is available to exchange data with a PC, depending on the specific application, and also recharges the internal Li-ion battery. The battery is capable of providing power for approximately 7 hours of operation."
For device demonstration see video here: